Someone preserved the files people uploaded to the now defunct dubstep forum (UK dubstep). Think a lot of it are recording from internet streams of live shows from private stations and some tape recordings. I'll try to find the original reddit link I got it from 

 https://www.reddit.com/r/realdubstep/comments/164adex/i_uploaded_117_earlymid2000_mixes_from_barefiles/ 

 I should put some of this on the next tape. Thanks for the tip!